Milk proteins are essential components found in milk, primarily categorized into two types: casein and whey. Casein makes up about 80% of the protein in cow's milk and forms curds when milk is coagulated. Whey protein, which accounts for the remaining 20%, is the liquid that separates during cheese production and is known for its high digestibility and rich amino acid profile. These proteins play a crucial role in nutrition, providing essential amino acids necessary for growth and repair in the body. They are also important in various food products, such as cheese and yogurt, and are commonly used in dietary supplements for athletes and fitness enthusiasts due to their muscle-building properties.